Far Lateral Disc Excision at L5–S1 Complicated by Iliolumbar Artery Incursion: Case Report

OBJECTIVE AND IMPORTANCE Paramedial approaches to far lateral discs at the L5–S1 space joint have advantages but may also bring the surgical space closer to large branch arteries of the internal iliac artery. I report incursion into an iliolumbar artery that required laparotomy to control hemorrhage. Surgeons performing extraforaminal disc explorations at L5–S1 need to evaluate preoperative magnetic resonance imaging scans for an enlarged iliolumbar artery near the disc space. CLINICAL PRESENTATION The patient presented with a right L5 radiculopathy and a far lateral disc at L5–S1, as indicated by analysis of her magnetic resonance imaging scan. INTERVENTION A midline incision and an extraforaminal exposure were performed. Arterial bleeding occurred when an anular disc fragment was removed with a pituitary rongeur under direct vision with microscopic magnification. Emergency laparotomy demonstrated hemorrhage from a branch of the internal iliac artery 2 cm from its origin. CONCLUSION Iliolumbar artery variants may be at the margins of extraforaminal disc exposure at L5–S1. Preoperative magnetic resonance imaging scans should be evaluated for this vasculature structure.